Extreme pressure lubricant



20 withstanding these high pressures.

Patented Jan. 14, 1941 PATENT OFFICE EXTREME PRESSURE LUBRICANT Henry G.Berger and Darwin E. Badertscher, Woodbury, and Francis M. Seger,Pltman, N. J assignors to Socony-Vacuum Oil Compa y, Incorporated, NewYork, N. Y., a. corporation of New York No Drawing. Original applicationDecember 3,

1937, Serial No. 177,891.

Divided and this application June 28, 1933, Serial No. 281,634

3 Claims.

the art of lubrication and is more particularly concerned with thedevelopment of a lubricant composition adapted for use under extremepres- 5 sure conditions.

As is well known to those familiar with the art, the ordinary type ofhydrocarbon lubricant, comprised only of a petroleum fraction, isincapable of withstanding the enormous pressures encountered betweenengaged surfaces in various types of modern machinery, such as thehypoid gears used in motor vehicles. This fact has led to thedevelopment of the so-called extreme pressure lubricant, which iscomprised of a suitable carrying agent, such as a mineral oil,containing a minor proportion of an ingredient which, under the extremepressure conditions encountered, will provide or form. between theengaged surfaces a lubricating film capable of Ingredients of the typejust referred to are known as extreme pressure ingredients or extremepressure (E. P.) bases, and numerous materials have been proposed forsuch use. Among the various E. P.

bases which have been proposed and which have met with varying degreesof success are organic materials which contain sulfur and chlorine. Ourpresent invention is related to this general type of compound. Thisapplication is a division of our copending application Serial No.177,891,

filed December 3, 1937.

It is a primary object of this invention to provide an extreme pressurelubricant which contains a new and novel sulfur-and-chlorine-contalningmaterial or compound capable of giving extreme pressure lubricantproperties to a carrying agent such as a hydrocarbon lubricant oilotherwise incapable of withstanding extreme pressure conditions. In thisregard we have dis.

covered that perchloromethyl mercaptan and the class or group ofcompounds obtained by reacting various reactive materials withperchloromethyl mercaptan are very effective extreme pressure lubricantaddition agents. The present invention 5 is concerned specifically withthe production of scribed and claimed in our copending applicationsSerial Nos. 177,891 and 177,890, filed December 3, 1937.

Perchloromethyl mercaptan is a chlorinated substituted sulfur chloridehaving the formula ClaC--SC1 and can be prepared by the chlorina- Thisinvention has to do in a general way with tion of carbon disulfideaccording to the method of Helfrich and Reid (JounAmeriChem. Soc. 43,591 (1921)). For example, carbon disuliide containing about .4% byweight of iodine was chlorinated in the absence of direct sunlight at atemperature maintained below 25 C. until the volume of the reactionmixture had doubled. This crude reaction product, which contains carbontetrachloride and sulfur chlorides in addition to perchloromethylmercaptan, can be used in the preparation of the lubricants contemplatedby this invention, but it is preferable to purify the crude product bydistillation on a water bath at 100 0., followed by steam distillation.Subsequent vacuum distillation of the material, refined in this mannerindicated that the steam distillated material was practically pure.

To demonstrate the effectiveness of perchloromethyl mercaptan as anextreme pressure lubricant ingredient we have prepared and testedcompositions comprised of a mineral oil to which perchloromethylmercaptan has been added. More specifically, we have added a minorproportion of perchloromethyl mercaptan to a mineral oil having aSaybolt Universal Viscosity of to 90 seconds at 210 F. and havesubjected samples of such blended lubricants to the Almen Pin test,described by Wolf and Mougey, Free. A. P. I., 1932, pages 118-130, andthe S. A. E. test, described in S. A. E. Journal 39, 234 (1936).

These two tests are commonly accepted in the art as standards todetermine the extreme pressure characteristics of a lubricant. In thetable below we show typical results obtained with such tests, using theoil alone and a sample of the same oil blended with perchloromethylmercaptan.

Extreme Pres- (1000 P. M. 14.6:1 rubbing ratio, 8.35 lbs/sec. loadiugrate Percent Product in on Almen Oil without addition agent 15Perchloromcthyl mercaptam.-. l

mercaptan used may vary irom say 0.1 per cent to 20 per cent, but ingeneral lower percentages, say from 0.1 per cent to 10 per cent, arepreierred.

Although we have indicated in the foregoing description that a minerallubricating oil is a preferred carrying agent for the extreme pressureingredients contemplated by our invention, it is not our intention thatthe invention be limited to any particular carrying or blending medium,but our invention includes broadly extreme pressure lubricantscontaining the perchloromethyl mercaptan described above, dissolved.dispersed, or emulsified in any other suitable carryin: medium, such,for example, as fatty vegetable such as kerosene, etc., benzene and rdrocarbons; alcohols, esters: ethers, etc.

captan.

We claim:

1. An extreme pressure lubricant comprising a hydrocarbon lubricant oilto which a minor proportion of perchloromethyl mercaptan has been added.

2. An extreme pressure lubricant comprising a hydrocarbon lubricant oilto which has been added a minor proportion of from about 0.1% to about10% of perchloromethyl mercaptan.

3. An extreme pressure lubricant comprising a viscous mineral oil towhich has been added about one percent of perchloromethyl mer- HENRY G.BERGER. DARWIN E. BADERTSCHER. FRANCIS M. SEGER.

